actix-web 处理程序中的 HTTP 请求 -> 一次有多个执行程序：EnterError

Question

在 actix-web 解析器中创建超级 post 请求时，会抛出以下错误 - 如何通过将请求生成到现有执行程序来发送一个 http 请求？

thread 'actix-rt:worker:1' panicked at 'Multiple executors at once: EnterError { reason: "attempted to run an executor while another executor is already running" }', src/libcore/result.rs:999:5
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
Panic in Arbiter thread, shutting down system.

main.rs

extern crate actix_web;
extern crate serde_json;
extern crate actix_rt;
extern crate hyper;

use serde_json::{Value, json};
use hyper::{Client, Uri, Body, Request};
use actix_web::{middleware, web, App, HttpResponse, HttpServer};
use actix_rt::System;
use actix_web::client;
use futures::future::{Future, lazy};

fn main() {
    println!("Start server...");
    listen();
}

pub fn listen() -> std::io::Result<()> {
    HttpServer::new(|| {
        App::new()
            .wrap(middleware::Logger::default())
            .data(web::JsonConfig::default().limit(4096))
            .service(web::resource("/push").route(web::post().to(index)))
            .service(web::resource("/test").route(web::post().to(test)))
    })
    .bind("127.0.0.1:8080")?
    .run()
}


fn index(item: web::Json<Value>) -> HttpResponse {
    println!("model: {:?}", &item);
    send(json!({
        "hello": "world"
    }));

    HttpResponse::Ok().json(item.0) // <- send response
}

fn test(item: web::Json<Value>) -> HttpResponse {
    println!("recevied test call!");
    println!("{:?}", &item);

    HttpResponse::Ok().json(item.0) // <- send response
}



pub fn send(mut data: serde_json::Value) {
    println!("# Start running log post future...");

    // if the following line is removed, the call is not received by the test function above
    System::new("test").block_on(lazy(|| {
        let req = Request::builder()
            .method("POST")
            .uri("http://localhost:8080/test")
            .body(Body::from(data.to_string()))
            .expect("request builder");

        let client = Client::new();
        let future = client.request(req)
        .and_then(|res| {
            println!("status: {}", res.status());
            Ok(())
        })
        .map_err(|err| {
            println!("error: {}", err);
        });
        return future;
    }));

    println!("# Finish running log post future")
}

cargo.toml

[package]
name = "rust-tokio-event-loop-madness"
version = "0.1.0"
authors = [""]
edition = "2018"

[dependencies]
serde_json = "1.0.39"
actix-web = "1.0.0"
serde_derive = "1.0.92"
actix-rt = "*"
hyper = "0.12.30"
futures = "*"

curl 命令触发错误：

curl -X POST -H 'Content-Type: application/json' -d '{"test":1}' http://localhost:8080/push

回购示例：https://github.com/fabifrank/rust-tokio-event-loop-madness

Answer 1

通过使用 tokio 函数 spawn 将 future 添加到 tokio 的运行执行器使其工作。

所以代替：

System::new("test").block_on(lazy(|| {

使用：

spawn(lazy(move || {

当然还要在 cargo.toml 中添加 tokio 作为依赖项并包含 crate。

Answer 2

这是因为 actix-web 从 1.0.0 版本开始使用 Tokio。正如 Reqwest 所做的那样，您最终得到两个运行次。

处理此问题的最佳方法之一是切换到您的处理程序和 reqwest 请求的异步版本。这个过程可能有点复杂，但在漫长的运行中是值得的。 This article 很好地解释了过渡。

actix-web 处理程序中的 HTTP 请求 -> 一次有多个执行程序：EnterError

HTTP request inside actix-web handler -> Multiple executors at once: EnterError

rust

rust-tokio

hyper

actix-web